Four-wheel drive mechanism for motor-vehicles.



T. F. LEDBETIER. FGUR-WHEEL omve MECHANISM FOR mama vEmcLEs.

APPLICATION HLED APR 39.19%L

- Patented Mar. 5, 1918.

2 SHEETS-SHEET I.

T. F. LEDBEYTER.

FOUR-WHEEL DRIVE MECHANiSM FOR MOTOR VEHICLES.

APPLICATION mm AN. 30. I917.

1,258, 1 2 6 Patented Mar. 5, 1918 2 SHEETS-SHEET 2.

7 in th out interfering with PATENT OFFICE.

THOMAS F. LEDBETTER, 0F COLUMBUS, GEORGIA.

FOUR-WHEEL DRIVE MECHANISM FOR MOTOR-VEHICLES.

To all whom it may concern:

Be it known that I, THOMAS F. Lnnnn'r- 'rsn, a citizen of the United States, residing at Columbus in the county of Muskogee and State 0 Georgia, have invented new and useful Improvements in FourJVhecl Drive Mechanism for MotorVehicles, of which the following is a specification.

This invention relates to motor vehicles, and has particular reference to a driving mechanism therefor.

The pur ose of my present invention is to provide a riving mechanism for connecting all four wheels of a motor vehicle with the source of power, this mechanism being very slmple in construction, efiicient in operation,

and of sufficient strength to resist strains to which it is subjected.

One of the main objects of my invention is to provide a four wheeled driving mechanism for motor vehicles in which the connection to one set of wheels may be easily disconnected or removed from the vehicle, when it is not desired, for any reason, to drive all four wheels, withoutafl'ecting or in anyway interfering with the connection between the source of power and the other set of wheels.

More particularly my invention has as its object to provide in a four-wheeled driving mechanism a difi'eren'tial mechanism for the front or steerin set of whee and asecond difi'erent ial mec anism for the rear wheels, both of these diiferential mechanisms being driven from a single drive shaft connected to the source of power, but the differentials belngindependent of each other so that thedifi'erential gearing for the front wheels and the connection between this gearing and the front wheels may be removed without disturbing the connection between the source of power and the rear wheels. Furthermore, in case of accident to the connection of the front wheels, the differential gearing therefor ma be lowered in its casing withany of the other connections.

The above and other objects of my invention are obtained in the structure described in the following specification and illustrated e accompanying drawings wherein- Figure 1 is a top plan view of a motor vehicle to which my improvements are applied, the body of the vehicle being removed.

Fig. 2 is a sectional view taken on a transverse line rearwardly of the front axle and Specification of Letters Patent.

Patented Mar. 5, 1918.

Application filed April 30, 1917. Serial No. 165,601.

showing the manner of mounting the front wheels.

Fig. 3 is a longitudinal view of the differential mechanisms, one side of each of the diflercntial casings being removed.

Fig. 4 is a sectional view taken transversely through the differential mechanism for the front wheels. I

Fig. 5 is a sectional view taken transversely through the difl'erential mechanism for the rear wheels.

Fig. 6 is a View, set of gears emplo mechanism for the rent wheels.

Referring to the drawings wherein like numerals represent like parts in the several views, 10 designates a chassis of an automobile which may be of any suitable construction that shown in the drawings being by way of illustration only. The rear wheels 11 are fixed to the outer ends of the rear shafts 12 which are rotatably mounted within the tubular axle sections 13. Mounted upon the inner ends of the shaft sections 13 is a casin 14 which houses a differential gearing mechanism 15 (see Fig. 5). The casing 14 is split longitudinally and at its forward end is open and provided with an outstanding flange 16.

In the present instance the differential gearing mechanism 15 comprises a large hollow gear wheel 17 having teeth upon its eriphery and carrying within its interior small gears 18 meshing with gears 19 fixed to the inner ends of the shaft sections 12. It is to be understood that while I have described a particular form of difl'erential gearing mechanism, any suitable type may be employed, that shown in the drawings being disclosed for illustrative purposes.

Secured to the forwardend of the casing 14 is a second casing 20 which houses the differential mechanism for the front wheels. The casing 20 is also split longitudinally into two parts of similar construction, these parts being removably secured togather by bolts 21 or the like. The casing 20 abuts at its rearward open end against the flange 16 and is removably secured thereto by bolts 22.

In the present case, a fixed shaft 23 extends transversely across the interior of the casing 20 and has its ends fixed in through openings in the walls thereof. The shaft 23 is fixed against rotation and comprises a single rod. Loosely mounted upon the partly in section, of a ed in the difi'erential nected blv shaft 23 is a differential mechanism 15 which is similar to the dille'rcntial 15 for the back wheels in that it; comprises a hollow gear 17 having teeth on its outer pe riphery and housing the intermeshing gears 18 and 19'. Each of the gears ltl is con' means of a sleeve 24 with a bevel gear 25 cated externall of the gear wheel 17'. The gears 19 may 0 integral with the sleeves 24 as shown in Fig. 4, or the gears 19' may be provided with a sleeve 24 adapted to telescope into and be splined to a. larger sleeve 24" fixed to the gear 25. as shown in Fig. 6. By the construction just described. it is to be noted that the ditl'crential mechanism for the front wheels floats or is looselv mounted upon the fixed shaft 23 so that the shaft may be removed longitudinallv from the casing 20 and when so removed. the differential will drop to the bottom of the casing.

26 desirrnatcs the source of power such an electric motor, or an internal combustidn enzine. A drive. shaft 27 extends rearwardlv from the source of power and over the gear wheels 17 and 17'. The shaft 27 has a worm near 28 meshing with the gear 17' of the differential for the front wheel. and a second worm gear 28 meshing with the pear 17 01 the differential located upon the rear axle. The shaft 27 is rotatablv mounted in bearing'surfaces 29 in the top of the casings 14 and 20. and it is maintained in place by caps '30, removably secured to the cas ngs.

The-front wheels 31 are driven from the d fferential 15' by means of connecting rods 3 ha i 'e upon their rear ends be el gears 33 m shing with the gears 25. The rear end of each of the rods 32 is mounted in a bearing 34 carried by the casing 20. and the front ends of th rods 32 are mounted in bear-inns carried bv brackets The front e d of each d ca i s a. gear fifi msliinfl w th a w er 37 carried on the inner end of a s uh shaf 38 to which the front. wheel 31 s secured.

Faehof the s ub shafts 38 is mounted in b ar ngs nrovided in spaced-apart upri hts 99 r n rom th fro t axle and connec d to 'e orhv m ans ofn bridg -niece 40. The r 'et 35 h ch s rws as azb r nq' member for h rod 3qrw+ends laterallv from thes -tnhq' Ti ttt ha s n that the shaft 38 s qi'hnnrt d in suitabl h arings to each side of h rlrivin" n ar 37. and that a simple but shafts 38 has bearings in both arms of the U-shaped yoke ll and is provided with a. universal joint 46 to permit turning movement of the front wheels. Extendin rearwardly from the yokes 41 are arms 4 connected by a transverse rod 48 SO-that the front steering wheels will mo:e in unison when the steering rod 49 is rotated.

It will be seen from the structure above described that the front wheels are driven from (me difl'erential and the rear wheels from a second differential and that both of the differentials are driven by the same source of power. By providing a differential for the front wheels which is distinct from the differential for the rear wheels, steering of the device is in no way interfered with. for when turning a curve the out side wheels, that is, the outside front wheel and the outside rear wheel, will rotate faster than the inside wheels. Furthermore, the ditl'erential for the front wheels and the con. uections between this differential and the front wheels may be readily removed from the vehicle when for any reason it is not desired to drive the front wheels. This is simply accomplished by removing the cap 30 from over the worm 28' and then removing the differential casing 20 together with its contained mechanismby withdrawing the bolts 22. The front ends of the rods 32 will then be withdrawn from their hearings in the bracts-ts 35. In the event that an oc- ('asion arises in which it is desired to disconnect the front wheels from the source of power when on a tour, it is only necessary to disconnect. the front wheels to remove the fixed shaft 23. upon which the difi'erential mechanism for the front ,whcels is mounted. longitudinally from the casing 20. The differential mechanism 15" will then drop to the bottom of the cas ng 20 and thus the, gear wheel 17' would he moved from mesh with the worm gear 28' of the drive shaft 27.

It is, of course. obvious that my invention is susceptible of various chances and mod fications which would be within the spirit of this.inrention without. \lenarting from the scope of the followng claims.

\Vbat l claim is:

1. To a four-wheel drive. a first difl'er-. ent al nearing for one s t of wheels. a casing therefor. a second differential gearing for the seco d set of wheels. :1 eas ntr for said second difl'crential gearine' adapted together with its contained parts to be em ved with out disturbing: said first different al gearin;:. and a source of power for driving said gear ngs.

2. To a four-wheel drive. a first differential eearin; for one set of wheels. a casing therefor. a second difl'erential gearingfor the other set of wheel-Land 'iudel'ielfldent of said first differential gearing a casing said second differential gearing, means for for detachably securing said second ,casin in position so that it may be removed wit iout disturbing said first differential gearing, and a source of power for driving said gearmgs.

3. In a four-wheel drive, a differential gearing for one set of wheels, a casing therefor, a second differential g-aring for the other set of wheels, a casing therefor, means for detachably securing the two casings together, a single drive shaft for both of said gearings, and a source of power for driving said drive shaft.

4. In a four-wheel drive, rear wheels, rear shafts for said wheels, a differential gearing for said rear wheels, a casing housing said differential gearing, front wheels, axles second differential gearing immediately in gearing, a gearing located adjacent to and front of said first differential casing for said second differential removably secured to said first casing, connections between said second differential gearing and the front axles, and a driving shaft having gears meshing with said differential gearings.

5. In a four-wheel drive, rear wheels, rear axle sections, rear shafts in said axle sections to which the rear wheels are fixed, front wheels, stu'b shafts carrying said front wheels, a first differential gearing on said rear shaft having a driven gear'wheel, a casing housing said first differential gearing, a second differential gearing for said front wheels located immediately in front of said first differential gearing and having a gear Wheel in alinement with said first gear wheel, a casing for said second differential gearing, connections between the second differential gearing and the front stub shafts, a'drive shaft extending through said casings immediately above said gear wheels and gears on said drive shaft meshing with said gear wheels of the differentials.

6. In a four-wheel drive, rear wheels, rear axle sections, rear shafts in said axle sections to wh ch the rear wheels are fixed, front wheels, stub shafts carrying said front wheels, :1 first differential gearing on said rear shafts having a driven gear wheel, a casing housing said first differential gearing, a second differential gearing for said front wheels locatedimmediately in front of said first differential gearing and having a gear wheel in alinement with said first gear wheel, a casing for said second differential gearing, means for detachably connecting said casings together, connections between the second differential gearing and the front stub shafts, a driveshaft extending through said casings immediately above said gear wheels, and gears on said drive shaft meshing with said gear wheels,

In a four-wheel drive, a differential gearing for the rear wheels, a casing therefor, a second differential gearing for the front wheels, a casing for said second differential gearing, means for detachably securing the two casings together so as to form substantially a single casing, hearings in the lop of each of said casings, a drive shaft rotatably mounted in said bearin s, a gear on sai drive shaft for the first differ ential gearing, a gear on the drive shaft for each of said differential gearings, and caps removably secured to said casings over said gears on the drive shaft.

In a four-wheel drive for motorvehicles, a first differential gearing for one set 'of wheels, a second differential gearing for the other set of wheels independent of said first differential gearing, a shaft on which said second differential gearing is rotatably or loosely mounted, connections between said second differential gearing and one set of wheels, and a single drive shaft for both of said differential earings, said shaft on which said second differential gearin is mounted being adapted to be remove to break the driving connection between said second differential gearing and the drive shaft without interfering with the connection between the drive shaft and the first differential gearing. i

9. In a four-wheel drive for motor vehicles, rear Wheels, rear shafts on which said rear w eels are mounted, a differential earing for said rear shafts front wheels, 5 afts on which said front wheels are mounted, a differential gearing for said front wheels, a casing for said second differential caring, a shaft on which said second di erential gearing is,loosely mounted and ada ted to e wit drawn to ermit the second d1fferential to drop tot e bottom of its casing, a single drive shaft for both of said gearings, and a source of power for driving said drive shaft.

10. In a four-wheel drive for motor vehicles, a first differential gearing for one set of wheels, a casing therefor, a second differential geari for the other set of wheels and indepen ent; of said first differential gearing, a casin for said second differential gearing, means or detachably securing said casing in place so that it may be removed without disturbing the first differential gearing, a fixed shaft extending through said second casing and upon which said second differential gearing is loosely mounted so that the shaft may be withdrawn to permit the differential gearing to drop to the bottom of its casing, and a source of power for driving said gearing.

11. Driving mechanism for motor vehicles comprising, in combination, a rear axle provided with a casing, shaft sections in said axle for the rear wheels, a differential gearing within said casing connected to said shaft sections, a second differential gearing for the front wheels, a casin for said second differential gearing detacha 1y connected to said first casing, a source of power, a single drive shaft bet-ween the source of power and said differential gearings, a frontaxle, stub shafts mounted in bearings on said front axle and adapted to receive the front steering wheels, a ear on each of said stub shafts, a pair 0 driven shafts each having a gear at its rear end meshin with its respective gear of said secon differential gearing, and a gear on the front end of each of said driven shafts in mesh with one of the gears on said stub shafts.

12. Driving mechanism for motor vehicles comprising, 1n combination, a rear shaft havin a casing, a first differential gearin in sai casing, rear shaft sections in sai axle, a second differential gearing for the front wheels, a casing housing sald second differential and detachably connected to said first casing, a front axle, stub shafts for the .front wheels mounted in hearings on the front axle, a yoke extending about said wheel and having hearings on the opposite sides of the wheel for the rece tion of said. stub shaft, a gear on each 0 said stub shafts, a air of driven shafts each having a gear at its front end in mesh with the ear on one of said stub shafts and a gear at Its rear end within said second casing and meshing with its respective gear of sai second diflerential gearing.

In testimony whereof I have hereunto set my hand.

THOMAS F. LEDBETTER. 

